In means of transportation such as motor vehicles or aircraft, electrical and/or electonic components are often embodied as microcomputers encapsulated within a housing. Control programs are stored in an assigned storage means and are activated in order, for example, to carry out the measurement of the temperature of the engine and to control or regulate the temperature of the engine by means of actuators, for example, final positioning elements. In order to actuate the sensors or actuators, actuation software or driver software is provided, said software bringing about not only the actuation of the sensors/actuators but also their data flow. Here, data are transmitted to the sensor/actuator via an internal interface of the device, and result data are transmitted back from the sensor/actuator via the interface in order to be further processed by the microcomputer.
The increasing use of electrical components in means of transportation, in particular in motor vehicles, and the increasing complexity of electronics has led to a situation in which the functionality and quality of the electrical processes and components have to be tested in various stages of the development phases. For this purpose, what are referred to as hardware-in-the-loop (HIL) systems are used in which the technical environment of a component is simulated in terms of the electrical input and output signals. During testing, the completely developed component is connected to the HIL system, which simulates the real vehicle environment of the component with its electrical actuation signals. The electrical behavior of the component is tested in terms of possible malfunctions by means of various test signals. In this way, electrical systems and components can be tested during the development phase, alone or in a component grouping, before the prototype of the vehicle exists.
Testing electrical components today requires that the component to be tested be adapted on a simulation computer. As control devices in vehicles today are encapsulated within a housing, a test procedure is problematical in particular if sensors, for example, measuring pickups or switches, or actuators, for example, motors or lamps, are arranged within the housing. In order to adapt the component to the simulation environment, it is then necessary to open the housing and disconnect signal lines in the control device and possibly connect them differently for test purposes.
As a result, a high degree of expenditure in terms of time and personnel is necessary when adapting new hardware states in control devices. The tested control devices are to a certain extent destroyed or damaged by the disconnection of existing signal lines so that after the test they can no longer be used in the vehicle.
DE 196 42 843 A1 discloses a method for checking the control device. In order to check the control device, some of the input signals of the control device are replaced by test signals.
EP 0 332 727 A1 discloses a device for testing electrical control devices in which the operating software of the control device is replaced by test software and the inputs and outputs of the control device are short-circuited by means of a plug-type connector. An external test monitor then displays the test data of the control device.